Serial proton magnetic resonance spectroscopy in lesions of Balò concentric sclerosis

OBJECTIVE

Balò concentric sclerosis is a rare demyelinating disorder. Serial proton magnetic resonance spectroscopic (1H-MRS) studies were carried out to better understand the biochemical changes within concentric lesions.

MATERIALS AND METHODS

Five concentric lesions in four patients with Balò concentric sclerosis were chosen as the objects of serial observation. They included two early acute lesions (showing as concentric ring enhancement on magnetic resonance imaging (MRI) after gadolinium administration), two late acute lesions (showing as marginal enhancement on MRI), and one early subacute lesion (showing as edematous concentric lesions without enhancement on MRI). The duration of follow-up ranged from 2-23 months (mean 10 months). A total of 20 1H-MRS studies were performed. On each 1H-MRS study, short-echo (30 ms) and long-echo (136 ms) spectra were obtained. The peaks of N-acetyl-asparate (NAA), choline-containing compounds (Cho), creatine and phosphocreatine (Cr), lactate, and mobile lipid were observed and compared.

RESULTS

Generally, a decrease of NAA/Cr ratio and an increase of Cho/Cr ratio were seen on all the spectra. Observing longitudinally, a trend of decreasing NAA/Cr ratio first and then partially recovering later was noted. The lowest level of NAA/Cr ratio was noted at the late acute stage or early subacute stage. The Cho/Cr ratio and amplitude of the lactate peak showed a similar trend as that of NAA/Cr, but in an opposite direction. It was rising first and descending later. The highest levels of Cho/Cr ratio and lactate peak were also observed at the late acute or early subacute stage. In addition, lactate peaks could be detected as long as 7 months after onset of symptoms. Lipid metabolite (two broad peaks at 0.9-1.5 ppm) was seen at the initial study of each group, but fluctuated in size on follow-up.

CONCLUSION

The characteristic biochemical changes of concentric sclerosis were a decreased NAA/Cr ratio, an increased Cho/Cr ratio, two broad peaks at 0.9-1.5 ppm, lactate production, and a reversible NAA/Cr ratio on follow-up. The serial 1H-MRS studies revealed a strong biochemical association between NAA, Cho, and lactate, which may be caused by the same pathogenetic process of demyelination and inflammatory cellular infiltration. The specificity of the serial changes may provide information about the stage of the concentric lesion and perhaps aid in monitoring progression of concentric lesions and evaluating therapy.

Risk of betel chewing for oesophageal cancer in Taiwan

Among 104 cases of squamous-cell oesophageal carcinoma patients and 277 controls in Taiwan, after adjusting for cigarette smoking, alcohol consumption, and other confounders, we found that subjects who chewed from 1 to 495 betel-year and more than 495 betel-years (about 20 betel quid per day for 20 years) had 3.6-fold (95% Cl = 1.3-10.1) and 9.2-fold risk (95% Cl = 1.8-46.7), respectively, of developing oesophageal cancer, compared to those who did not chew betel.

Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan

OBJECTIVE

To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan.

METHODS

TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method.

RESULTS

The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients.

CONCLUSION

TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.

Variability in aflatoxin-albumin adduct levels and effects of hepatitis B and C virus infection and glutathione S-transferase M1 and T1 genotype

Exposure to aflatoxin B1 (AFB1), an important cofactor in the etiology of hepatocellular carcinoma in Taiwan, is influenced by dietary and other factors. The present study examined the intraindividual variability in AFB1-albumin adducts, the most reliable long-term biomarker of AFB1 exposure, and whether the baseline or follow-up adduct levels and the intraindividual variability in adduct levels are modified by endogenous and environmental factors. The study measured AFB1-albumin adduct levels among 264 healthy male residents of three townships (Hu-Hsi, Ma-Kung, and Pai-Hsa) of Penghu Islets, Taiwan, at two different time points with a median interval of 1.68 years (range 1.00-3.17 years). There was a generalized reduction in the adduct levels, with the median values being 22.1 pmol/mg (range 5.0-355.8 pmol/mg) at time 1 and 14.3 pmol/mg (range 5.0-205.2 pmol/mg) at time 2. This intraindividual variability in adduct levels was inversely associated with the age of subjects and the time interval between the two blood draws. The variability in adduct levels was lower among subjects in Hu-Hsi and Pai-Hsa townships as compared to those in Ma-Kung. No significant association was observed for the intraindividual variability in AFB1-albumin adducts with regard to the season when blood was drawn. There was also no significant association between intraindividual variability and hepatitis B surface antigen, anti-hepatitis C virus (anti-HCV), glutathione S-transferase (GST) M1, or GSTT1 status. In conclusion, we found substantial intraindividual variability in the AFB1 exposure (as determined by AFB1-albumin adducts) in Taiwan, which was probably more likely related to dietary or other environmental influences rather than to endogenous factors (e.g., hepatitis B/C viral infection or GST M1/T1 genetic status).

Genetic polymorphisms of glutathione S-transferases M1 and T1 associated with susceptibility to aflatoxin-related hepatocarcinogenesis among chronic hepatitis B carriers: a nested case-control study in Taiwan

This study was conducted to investigate the modifying effect of glutathione S-transferase (GST) M1 and T1 polymorphisms on aflatoxin-induced hepatocarcinogenesis among chronic hepatitis B virus surface antigen (HBsAg) carriers. A total of 79 HBsAg-positive cases of hepatocellular carcinoma (HCC) diagnosed between 1991 and 1997 were identified and individually matched to one or two HBsAg-positive controls on age, gender, residence and date of recruitment from the same cancer screening cohort in Taiwan. Blood samples were tested for hepatitis B and C viral markers by enzyme immunoassay and for aflatoxin B(1) (AFB(1))-albumin adducts by competitive enzyme-linked immunosorbent assay. GSTM1 and GSTT1 genotypes were determined by PCR. There was a statistically significant relationship between detectable levels of AFB(1)-albumin adducts in serum and risk of HCC among chronic HBsAg carriers, with an adjusted odds ratio (OR) of 2.0 [95% confidence interval (CI) 1.1-3.7]. In addition, the effect of aflatoxin exposure on HCC risk was more pronounced among chronic HBsAg carriers with the GSTT1 null genotype (OR 3.7, 95% CI 1.5-9.3) than those who were non-null (OR 0.9, 95% CI 0.3-2.4). The interaction between serum AFB(1)-albumin adduct level and GSTT1 genotype was statistically significant (P = 0.03). For GSTM1 the effect of aflatoxin exposure on HCC risk in those with the null genotype was also greater (adjusted OR 2.8, 95% CI 1.0-7.8) than in those with the gene present (adjusted OR 1.8, 95% CI 0.8-4.5), but the difference was not significant (P = 0.91). Notably, when the interaction between aflatoxin exposure and GSTT1 genotype was considered, aflatoxin exposure by itself was not a significant determinant of HCC risk among chronic HBsAg carriers. These results demonstrate the importance of gene-environment interactions in the multifactorial development of HCC.

Genetic polymorphisms of XRCC1 and risk of the esophageal cancer

A variety of environmental factors were identified to be associated with the risk of esophageal cancer. The variation in capacity of DNA repair might influence environmental chemical-associated carcinogenesis. We hypothesized that the polymorphic XRCC1 genes might modify cancer susceptibility of the esophagus. To investigate the effect of XRCC1 genetic polymorphisms on codons 194, 280 and 399, we evaluated data from 105 patients of esophageal squamous cell carcinoma and 264 healthy controls, matching with age (+/-3 years), gender and ethnicity. The distribution of the 3 genotypes were not significantly different among patients and controls. However, among alcohol drinkers, the XRCC1399 Arg/Arg genotype was more frequently found in patients with esophageal cancer. After adjustment with other environmental confounders, the OR for the genotype of XRCC1399 Arg/Arg was 2.78 (95% CI =1.15-6.67) as compared with the XRCC1(399) Arg/Gln and XRCC1(399) Gln/Gln genotypes in the alcohol drinkers. Similar trends were observed among cigarette smokers and areca chewers. However, they did not reach a statistical significance. Our findings suggest that the polymorphic XRCC1 genes might modify the risk of alcohol-associated esophageal cancers.

Genetic polymorphisms of XRCC1 and risk of the esophageal cancer

A variety of environmental factors were identified to be associated with the risk of esophageal cancer. The variation in capacity of DNA repair might influence environmental chemical-associated carcinogenesis. We hypothesized that the polymorphic XRCC1 genes might modify cancer susceptibility of the esophagus. To investigate the effect of XRCC1 genetic polymorphisms on codons 194, 280 and 399, we evaluated data from 105 patients of esophageal squamous cell carcinoma and 264 healthy controls, matching with age (+/-3 years), gender and ethnicity. The distribution of the 3 genotypes were not significantly different among patients and controls. However, among alcohol drinkers, the XRCC1399 Arg/Arg genotype was more frequently found in patients with esophageal cancer. After adjustment with other environmental confounders, the OR for the genotype of XRCC1399 Arg/Arg was 2.78 (95% CI =1.15-6.67) as compared with the XRCC1(399) Arg/Gln and XRCC1(399) Gln/Gln genotypes in the alcohol drinkers. Similar trends were observed among cigarette smokers and areca chewers. However, they did not reach a statistical significance. Our findings suggest that the polymorphic XRCC1 genes might modify the risk of alcohol-associated esophageal cancers.

Association of immune responses and ischemic brain infarction in rat

Inflammation plays an important role in the pathogenesis of neurodegenerative diseases including ischemia. Occlusion of common carotid artery and middle cerebral artery has been used to produce focal ischemic lesions in the rat. Here, we examined the associations between immune reactions and postischemic brain infarction. Ischemia/reperfusion time-dependently caused brain infarction. The kinetics of inflammatory reactions in rat brain including inflammatory cell infiltration, edema formation, cytokines/chemokines and adhesion molecules production and matrix metalloproteinase activation were relevant to the progression of ischemic infarction. Differential induction profile after ischemia suggests that this activation might contribute to secondary brain damage in ischemic tissues. On the other hand, another possibility of this response is to trigger processes that mediate the neural regeneration after ischemic injury.

In situ detection of hTERT mRNA relates to Ki-67 labeling index in papillary thyroid carcinoma

BACKGROUND

Telomerase is activated in most human cancers but is inactivate in adult somatic tissues except for some proliferating cell lineages. The maintenance of telomerase activity may be a critical step of cellular immortalization and transformation.

MATERIALS AND METHODS

We analyzed the expression of human telomerase reverse transcriptase (hTERT) using in situ hybridization and compared it to Ki-67 immunoreactivity in 29 cases of papillary thyroid carcinoma (PTC) and 17 cases of benign thyroid disease.

RESULTS

The hTERT messenger RNA (mRNA) was expressed in the cytoplasm of carcinoma cells with moderate (n = 10) to strong intensity (n = 10) in 69% (20 of 29) PTC cases. Human TERT was found in only 29% (5 of 17) cases of benign thyroid disease. Human TERT gene expression was preferentially detected in PTC (P = 0.021). The Ki-67 labeling index was observed in 16 cases of PTC (16 of 29; 55.2%). This result was significantly different from that of benign thyroid disease (P = 0.014). The Ki-67 labeling index related to the intensity of hTERT mRNA expression (r = 0.51; P = 0.005) and was inversely associated with the follicular variant of PTC (r = -0.413; P = 0.026). No statistically significant difference was found between hTERT expression and histological subtype of PTC.

CONCLUSIONS

Our results demonstrated that expression of hTERT could be detected using in situ hybridization in PTCs and was significantly distinguishable from that of benign thyroid disease. Human TERT expression was related to the Ki-67 labeling index, indicating that coupling of telomerase activation with cell proliferation was the associated mechanism for tumorigenesis.

Tobacco, betel quid, alcohol, and illicit drug use among 13- to 35-year-olds in I-Lan, rural Taiwan: prevalence and risk factors

OBJECTIVES

This study determined the prevalence of and risk factors for substance use among rural Taiwanese.

METHODS

We used a survey of a representative sample of 6318 participants aged 13 to 35 years in I-Lan, Taiwan, in 1996 through 1997.

RESULTS

Perceived use of illicit drugs by peers, tobacco smoking, betel quid chewing, and male gender were the strongest predictors of illicit drug use. The prevalence of illicit drug use ranged from 0.3% among those who did not use any other substance to 7.1% among those using tobacco, betel quid, and alcohol.

CONCLUSIONS

Preventive measures should address substance use in general rather than aiming at single substances.

An intervention trial on efficacy of atropine and multi-focal glasses in controlling myopic progression

PURPOSE

This randomized clinical trial assessed the treatment effects of atropine and/or multi-focal lenses in decreasing the progression rate of myopia in children.

METHODS

Two hundred and twenty-seven schoolchildren with myopia, aged from 6 to 13 years, who were stratified based on gender, age and the initial amount of myopia were randomly assigned to three treatment groups: 0.5% atropine with multi-focal glasses, multi-focal glasses, and single vision spectacles. Each subject was followed for at least eighteen months. These results report on the 188 patients available for the follow-up.

RESULTS

The mean progression of myopia in atropine with multi-focal glasses group (0.41 D) was significantly less than the multi-focal (1.19 D) and single vision group (1.40 D) (p < 0.0001). But no significant difference was noted between the last two groups (p = 0.44). The progression of myopia was significantly correlated with the increases of axial length (r = 0.65, p = 0.0001), but not with the changes of corneal power (r=-0.09), anterior chamber depth (r = -0.023), lens thickness (r = -0.08), or intra-ocular pressure (r = -0.008).

CONCLUSION

The 0.5% atropine with multi-focal lenses can slow down the progression rate of myopia. However, multi-focal lenses alone showed no difference in effect compared to control.

Arginase levels are increased in patients with rheumatoid arthritis

Arginase and nitric oxide synthase (NOS) compete for the same substrate, L-arginine. The reciprocal regulation of arginase and NOS in L-arginine-metabolizing pathways has recently been demonstrated. Since NOS is involved in the inflammation of human arthritides, we hypothesized that this reciprocal regulation might also occur within the inflamed synovium. The present study shows that both serum arginase activity and protein levels were significantly higher in patients with rheumatoid arthritis (RA) than in patients with systemic lupus erythematosus (SLE) or osteoarthritis (OA) or in healthy controls. Arginase protein concentrations in supernatants of monocyte cultures from RA patients were also significantly higher than in those from SLE or OA patients or healthy controls. In RA patients, there was a significant correlation between the serum concentrations of arginase protein and rheumatoid factor (r = 0.82, p < 0.0001). These data indicate that increased arginase production is seen in RA patients, but not in other immune-related diseases, suggesting that increased arginase production is unique to, and may play an important role in, the pathogenesis of RA disease.

Risk factors associated with hepatitis C virus infection in Taiwanese government employees

This study evaluated the roles of multiple factors in hepatitis C virus (HCV) infection, with emphasis on the modification of various individual characteristics on the risk associated with percutaneous exposure to blood. Serum samples taken from 4869 men in Taiwan within a cohort study were tested for HCV antibody. The overall positive rate of anti-HCV was 1.6%. In a logistic regression, factors positively associated with anti-HCV positivity were previous blood transfusion (odds ratio [OR] = 7.28: 95% confidence interval [CI] = 4.26-12.45), a history of surgery (OR = 2.06: 95% CI = 1 23-3.46), and lower educational levels (OR = 1.94; 95% CI = 1.14-3.32). The anti-HCV positive rate was significantly lower in hepatitis B surface antigen (HBsAg) carriers than in non-carriers (OR = 0.60; 95% CI = 0.37-0.95). Ageing, lower educational levels, O blood group, and Taiwanese ethnicity enhanced the likelihood of HCV infection through blood transfusion/surgery, whereasHBsAg status, cigarette smoking, and habitual alcohol drinking reduced it.

Cerebral ischemia/reperfusion injury in rat brain: effects of naloxone

The pathogenesis of cerebral ischemia/reperfusion (I/R) involves cytokine/chemokine production, inflammatory cell influx, astrogliosis, cytoskeletal protein degradation and breakdown of the blood-brain barrier. (-)-Naloxone is able to reduce infarct volume and has been used as a therapeutic agent for cerebral I/R injuries. However, its effects on the mentioned pathophysiologic changes have scarcely been addressed. Cerebral I/R was produced by occluding and opening bilateral common carotid artery and unilateral middle cerebral artery in Sprague-Dawley rats. After cerebral I/R, the degradation of neuronal microtubule-associated protein-2 (MAP-2) was strongly associated with astrogliosis, inflammatory cell infiltration, cytokine/chemokine overproduction, and matrix metalloproteinase-9 activation. (-)-Naloxone pretreatment suppresses post-ischemic activation and preserves more MAP-2 protein. Therefore, (-)-naloxone administration might be an effective therapeutic intervention for reducing ischemic injuries.

Use of bacterially expressed EBNA-1 protein cloned from a nasopharyngeal carcinoma (NPC) biopsy as a screening test for NPC patients

EBV serological tests have been used for many years as accessory diagnostic predictors of nasopharyngeal carcinoma (NPC). To increase the sensitivity and specificity of the NPC detection rate, a novel enzyme-linked immunosorbent assay (ELISA) was established using a bacterially-expressed GST-EBNA-1 protein, containing the EBNA-1 sequence cloned from an NPC patient. Serum samples were collected from age- and gender-matched patients with NPC, community control subjects and hospital control patients and tested using this ELISA. The positivity rates were 78.7% (247/314) in NPC, 11.5% (28/244) in hospital controls and 3.8% (10/263) in the community control group. These serum samples were also tested for IgA anti-VCA antibodies and their ability to neutralize EBV DNase and the sensitivities of the anti-VCA antibody and DNase-neutralization tests also were analyzed. The optimum combination is VCA plus EBNA-1, which can identify 92.5% (287/310) of NPC patients, and shows a specificity of 92.7% (242/261) for normal individuals.

HLA-DQA1 genotyping in patients with rheumatoid arthritis in Taiwan

To investigate the role of HLA-DQA1 genotypes and their interaction with HLA-DRB1 in the pathogenesis of rheumatoid arthritis (RA) in Taiwan, HLA-DQA1 was determined in 71 patients with RA and 108 healthy controls by SSP-PCR method. HLA-DRB1 and HLA-DQA1 were simultaneously detected in 55 RA patients and 101 healthy controls. PCR/SSOP method was used to determine the HLA-DRB1 genotypes, and the subtypes of HLA-DR4 were determined by cloning and sequencing. The phenotypic frequency of HLA-DQA1*0301 was significantly lower in RA than in controls, and, in contrast, the HLA-DQA1*0302 and DQA1*0303 were significantly higher in RA than in controls. The associations of DQA1*0301, *0302, and *0303 with RA were independent of DR4 and DRB1*0405. Moreover, the interactions between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303 could enhance the development of RA. We also found that the prevalence of bone erosion and seropositivity of rheumatoid factor (RF) were significantly higher in HLA-DQA1*0303 positive RA patients than in healthy controls. HLA-DQA1*0302 and DQA1*0303 are the risk factors for susceptibility to RA, while HLA-DQA1*0301 is a protective factor. A synergistic effect for the susceptibility to RA can be found between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303. We also found that the HLA-DQA1*0303 was related to bone erosion and seropositivity of RF in RA patients.

Familial Mediterranean fever in a Taiwanese patient

Familial Mediterranean fever is a rare disease characterized by cyclic attacks of fever, serositis and strong family background. Here we report a 22-year-old man who suffered from recurrent fever accompanied by chest and abdominal pain for more than 10 years. The attack frequency was about once per 2-3 weeks. Although he consulted many clinics and even received appendectomy at the age of 15, no definite diagnosis was given. During the admission, many laboratory examinations failed to show any abnormality except mild leukocytosis and elevated C-reaction protein. Image studies including chest X ray and abdominal CT scan showed negative result but, interestingly, Gallium-67 scan showed a hot spot in right lower chest and right lower abdomen. After prophylaxis with colchicine 1.0 mg per day, he has enjoyed more than 2 years without the above symptoms.

Knowledge and perception of oral health promotion in schools among dental nurses in Sarawak, Malaysia

In recent years, the concept of a Health-Promoting School has received much interest. In Malaysia, dental nurses are ideally placed to play a lead role in promoting Oral Health within the school setting. This study aims to provide information on the knowledge, perception and perceived role of Oral Health Promotion in schools, among dental nurses. A postal questionnaire was used to measure dental nurses' knowledge, perception and perceived role of Oral Health Promotion. The majority (60%) of dental nurses had good knowledge of Oral Health Promotion. Generally, they perceived that they play an important role in promoting Oral Health in schools. However, a sizeable proportion (25%) did not think they had a role to play in working together with school authorities to provide children with healthy food choices in school canteens. The majority (60%) of dental nurses did not perceive Oral Health Promotion to be important as a whole. They had a good perception of the concepts: it supports behaviour change, it has appropriate goals, it integrates oral health and general health and relieves anxiety. However, they had a poorer perception of the concepts; diverse educational approaches, participation, focus on prevention, early intervention, "spread of effect" of dental health education and "make healthier choices the easier choices". Years of service was not significantly associated with knowledge and perception of Oral Health Promotion. Dental nurses should be reoriented towards a more holistic practice of Oral Health Promotion. Workshops that invite active participation from dental nurses should be conducted to equip them with the necessary knowledge and skills.

Incidence of transitional cell carcinoma and arsenic in drinking water: a follow-up study of 8,102 residents in an arseniasis-endemic area in northeastern Taiwan

A significant association between ingested arsenic and bladder cancer has been reported in an arseniasis-endemic area in southwestern Taiwan, where many households share only a few wells in their villages. In another arseniasis-endemic area in northeastern Taiwan, each household has its own well for obtaining drinking water. In 1991-1994, the authors examined risk of transitional cell carcinoma (TCC) in relation to ingested arsenic in a cohort of 8,102 residents in northeastern Taiwan. Estimation of each study subject's individual exposure to inorganic arsenic was based on the arsenic concentration in his or her own well water, which was determined by hydride generation combined with atomic absorption spectrometry. Information on duration of consumption of the well water was obtained through standardized questionnaire interviews. The occurrence of urinary tract cancers was ascertained by follow-up interview and by data linkage with community hospital records, the national death certification profile, and the cancer registry profile. Cox proportional hazards regression analysis was used to estimate multivariate-adjusted relative risks and 95% confidence intervals. There was a significantly increased incidence of urinary cancers for the study cohort compared with the general population in Taiwan (standardized incidence ratio = 2.05; 95% confidence interval (CI): 1.22, 3.24). A significant dose-response relation between risk of cancers of the urinary organs, especially TCC, and indices of arsenic exposure was observed after adjustment for age, sex, and cigarette smoking. The multivariate-adjusted relative risks of developing TCC were 1.9, 8.2, and 15.3 for arsenic concentrations of 10.1-50.0, 50.1-100, and >100 microg/liter, respectively, compared with the referent level of < or =10.0 microg/liter.

Differential effects of cytokines and redox potential on glutamate uptake in rat cortical glial cultures

Perturbation of glutamate uptake may contribute to the pathogenesis of neuronal damage in the central nervous system. Cytokine overproduction, oxidative stress, energy failure, and metabolic impairment are commonly concomitant or resultant consequences of brain injury, which might synergistically exacerbate neuronal damage. In this study, we elucidate the effects of these events on glutamate uptake. Rat cortical glial cultures lowered the concentration of extracellular glutamate via glutamate transporters. Disturbance of ionic gradients, energy depletion, and reduced metabolic function impaired glutamate transporter activity. Tumor necrosis factor-alpha and interleukin (lL)-1beta potentiated glutamate-mediated oxidative stress and finally resulted in decrease in glutamate transporter activity. However, IL-4 and IL-10 exhibited no significant effects on both events. These results suggest that oxidative stress has a potential neurotoxicity by means of impairing glutamate transport into astrocytes.

Should asymptomatic atrophic retinal holes be treated prophylactically in pseudophakic eyes after Nd:YAG laser posterior capsulotomy?

BACKGROUND

Retinal detachment (RD) following cataract extraction is a serious and potentially sight-threatening event that will often necessitate further surgical intervention. Of the several risk factors reported in the literature, Neodymium:YAG laser posterior capsulotomy has been reported to increase the risk of RD following cataract surgery up to 4.9-fold. The purpose of this study is to investigate the difference of characteristics in pseudophakic RD with or without Nd:YAG laser posterior capsulotomy and the possible role of atrophic retinal holes in pseudophakic RD after posterior capsulotomy.

METHODS

Retrospective review of 78 cases of pseudophakic RD after uncomplicated extracapsular lens extraction and intraocular lens implantation was done. Twenty-one of them received Nd:YAG laser posterior capsulotomy before RD. We measured the numbers, types, and locations of retinal breaks and several other risk factors associated with RD. Analysis was performed with the system of Statistical Products and Services Solutions (SPSS).

RESULTS

The ratio of retinal holes only in retinal breaks that caused retinal detachment was significantly higher in the capsulotomy group than the non-capsulotomy group (12/21 vs 14/57, p = 0.05). Only three patients in the capsulotomy group claimed significant symptoms before the detachment. There was no significant difference in mean number of retinal breaks and break location. Other risk factors predisposing to RD did not differ significantly between the two groups (13/21 vs 23/57, p = 0.12), nor did the interval from cataract surgery to RD (31.20 vs 29.44 months, p = 0.48).

CONCLUSIONS

This primitive study suggests that asymptomatic atrophic retinal holes, usually not regarded as an absolute risk factor for RD, might lead to RD preferentially after Nd:YAG laser posterior capsulotomy. Early identification and treatment of such breaks might decrease the incidence of pseudophakic RD. We suggest that it is necessary to perform detailed preoperative and postoperative fundus examination and treat prophylactically any identified breaks, including asymptomatic atrophic retinal holes, in pseudophakic eyes after Nd:YAG laser posterior capsulotomy.

Stimulation of CREB binding protein nucleosomal histone acetyltransferase activity by a class of transcriptional activators

The transcriptional coactivator CREB binding protein (CBP) possesses intrinsic histone acetyltransferase (HAT) activity that is important for gene regulation. CBP binds to and cooperates with numerous nuclear factors to stimulate transcription, but it is unclear if these factors modulate CBP HAT activity. Our previous work showed that CBP interacts with the Epstein-Barr virus-encoded basic region zipper (b-zip) protein, Zta, and augments its transcriptional activity. Here we report that Zta strongly enhances CBP-mediated acetylation of nucleosomal histones. Zta stimulated the HAT activity of CBP that had been partially purified or immunoprecipitated from mammalian cells as well as from affinity-purified, baculovirus expressed CBP. Stimulation of nucleosome acetylation required the CBP HAT domain, the Zta DNA binding and transcription activation domain, and nucleosomal DNA. In addition to Zta, we found that two other b-zip proteins, NF-E2 and C/EBPalpha, strongly stimulated nucleosomal HAT activity. In contrast, several CBP-binding proteins, including phospho-CREB, JUN/FOS, GATA-1, Pit-1, and EKLF, failed to stimulate HAT activity. These results demonstrate that a subset of transcriptional activators enhance the nucleosome-directed HAT activity of CBP and suggest that nuclear factors may regulate transcription by altering substrate recognition and/or the enzymatic activity of chromatin modifying coactivators.

Perinatal factors and risk of neuroblastoma

Neuroblastoma is a malignancy commonly diagnosed during infancy or early childhood, raising speculation about the role of perinatal factors and risk of disease. Using a case-control design, cases included 155 infants and children aged 0-5 years with histologically confirmed neuroblastoma diagnosed and reported to the New York State Cancer Registry between 1976 and 1987. Controls were randomly selected from the State's Livebirth Registry and were frequency matched to cases on year of birth (n = 310). Medical records of cases were used to verify histology and stage of disease. Data on perinatal factors were ascertained from birth certificates and standardised telephone interviews with mothers. Unconditional logistic regression was used to estimate (un)adjusted odds ratios (OR) and 95% confidence intervals (CI). Both preterm (< 37 weeks) and post-term (> 42 weeks) birth were associated with a reduction in risk (OR = 0.4 [CI = 0.1, 0.9] and OR = 0.3 [CI = 0.1, 0.7] respectively) after controlling for confounders in unconditional logistic regression analysis. Elevated risk factors included: smoking during pregnancy (OR = 1.6; CI = 0.9, 2.8), contracted pelvis (OR = 2.3; CI = 0.6, 9.8), birth injury (OR = 2.9; CI = 0.3, 24.9) and 1-min Apgar Score < or =3 (OR = 6.0; CI = 0.9, 38.6); all confidence intervals included one. These data suggest that extremes in gestation may be associated with a reduced risk, although aetiological mechanisms remain unknown.

MRI of intraosseous dural arteriovenous malformation: findings in two cases

Intraosseous dural arteriovenous malformation (DAVM) is rare. The intraosseous component of this DAVM has usually been neglected on conventional angiography and found during operation after the bone drilling has been completed. Considerable bleeding usually occurs during operation because of the unexpected hypervascular bone marrow. We report the use of MRI to help in the diagnosis and therapeutic plan for this rare type of DAVM.